1. Field of the Invention
The present invention relates to an electromagnetic linear control valve and more particularly to an improvement in electromagnetic linear control valves in which the moving core without a wound solenoid moves linearly and controls the opening of the valve in accordance with variation of the applied current of the solenoid by electromagnetic induction.
2. Description of the Prior Art
A conventional electromagnetic valve is disclosed, for example, in U.S. Pat. No. 3,712,581 granted on Jan. 23, 1973 to Parlow. In such conventional electromagnetic valve, the magnetic path of the moving core includes a gap which is positioned in the moving direction of the moving core, and the moving core is operatively connected to a valve element.
Consequently, it is difficult to linearly control the opening of the valve in accordance with variation of current applied to the solenoid because the gap is changed by the moved position of the moving core, and the torque of the moving core by the electromagnetic induction is inversely proportional to the square of the dimension of the gap.